High molecular weight linear polyamides from araliphatic diamines

ABSTRACT

This invention relates to high molecular weight linear polyamides and co-polyamides which are obtained by meltcondensation of an araliphatic diamine containing one aromatic and one aliphatic amino group in its molecule, with an aliphatic dicarboxylic acid, optionally in admixture with a salt of an aliphatic dicarboxylic acid and an aliphatic diamine and/or of a lactam, and to foils and fibres produced from these polyamides and co-polyamides.

United States Patent [191 Christoph et al.

[ HIGH MOLECULAR WEIGHT LINEAR POLYAMIDES FROM ARALIPHATIC DIAMINES [75] Inventors: Geert Christoph; Eduard Radlmann; Giinther Nischk, all of Dormagen, Germany [73] Assignee: Bayer Aktiengesellschaft,

Leverkusen, Bayerwerk, Germany [22] Filed: Mar. 11, 1974 [21] Appl. No.: 450,209

Related US. Application Data [63] Continuation of Ser. No. 269,840, July 7, I972,

abandoned.

[30] Foreign Application Priority Data July 9, i971 Germany l. 2134l72 [52] US. Cl..... 260/47 CZ; 260/302; 260/308 DS; 260/3246 N; 260/334 R; 260/33.4 P; 260/78 R; 260/78 A [111 3,893,975 [451 July 8,1975

[5i] Int. Cl C08g 20/20 [58] Field of Search 260/47 CZ, 78 R, 78 A [56] References Cited UNITED STATES PATENTS 9/1938 Carothers 18/54 l/l953 Kirby 260/78 Primary Examiner-Lester L. Lee Attorney, Agent, or FirmPlumley & Tyner [5 7] ABSTRACT 5 Claims, No Drawings mixtures. in this case, they show outstanding filmforming properties.

Accordingly, the invention relates to novel, high molecular weight, linear polyamides consisting essentially This invention relates to high molecular weight linear 5 0f polyamides and co-polyamides which are obtained by melt-condensation of an araliphatic diamine containing a. I00 to 1 mol of recurring structural elements corresponding to the general formula one aromatic and one aliphatic amino group in its molecule, with an aliphatic dicarboxylic acid, optionally in admixture with a salt of an aliphatic dicarboxylic acid and an aliphatic diamine and/or of a lactam, and to filaments and fibres produced from these polyamides and co-polyamides.

A number of polamides having aromatic amide groups are known, which are obtained by meltcondensation or interfacial condensation of binary systems of aliphatic diamines/aromatic dicarboxylic acids or aromatic diamines/aliphatic dicarboxylic acids. If the ternary system aliphatic diamine/aromatic diaminelaliphatte dicarboxylic acid is used for condensation, copolyamides containing aliphatic and aromatic amide groups in pure statistical distribution are obtained.

Other polyamides and processes for their production are also known, which are obtained by polycondensation of araliphatic diamines with, for example, cycloaliphatic and heterocyclic dicarboxylic acids (8. F. Smirnova-Zamkova in Ukrainskij chimiceskij zurnal 30, 208-219, 1964). In this reference, however, araliphatic diamines are always understood to be diamines of the kind which, although containing an aromatic ring in the molecule, always contain the amino group attached to it through an alkylene radical.

It has now been found that, where aliphatic diamines of the kind which contain an amino group directly attached to the aromatic ring and the second amino group attached to the aromatic ring through an alkylens group, are used with aliphatic dicarboxylic acids, it is possible to obtain novel polyamides or, by the addition of other polyamide formers, for example, AH-salt or c-caprolactam, novel copolyamides by polycondensation which give high-viscosity, substantially colourless melts with good film-forming and filament-forming properties.

One particularly important property of these copolyamides is their solubility in highly polar solvents such as dimethyl formamide, dimethyl acetamide, dimethyl sulphoxide and N-methyl pyrrolidone. Furthermore, those copolyamides which are produced with caprolactam and which contain more than by weight of araliphatic diamines, are soluble to an extent of up to 50% by weight in methanol or methanol-water and A ll l. H

wherein:

R represents a linear or branched alkylene radical with 4 to l0 carbon atoms;

R, represents a substituted or unsubstituted radical selected from the group consisting of 1,3-phenylene, 1,4-phenylene, l,4-naphthylene, 1,5-naphthylene, 4,4'-diphenylene, 4,4'-diphenylene substituted one or more times by halogen or lower alkyl groups and a radical substituted one or more times by halogen or lower alkyl groups or unsubstituted of the general formula wherein:

Z is a number selected from the group consisting of O-, S, CH (CH and n is an integer from 1 to 4; and

b. 0 to 99 mol of recurring structural elements corresponding to the general formula selected from the group consisting of lF 'lT Ilii ll and mixtures thereof wherein: R represents a radical selected from the group consisting of 1,3-phenylene, 1,4-phenylene, and 4,4-

diphenylene ether, wherein the substituent is one or more chlorine atoms; and R, is a radical selected from the group consisting of said polyamide having a relative solution viscosity in the range from 1.1 to 4.0 as measured on a solution of l g of polyamide in 100 ml of m-cresol at 25C.

A further object of this invention is a process for the production of high molecular weight linear polyamides having relative solution viscosities in the range from 1.1 to 4.0 as measured on a solution of 1 g of polyamide in I ml of m-cresol at 25C, which comprises polycondensing in the melt in the absence of oxygen in an inert gas atmosphere at temperatures of from 100 to 300C and at pressures between normal pressure and 0.001 Torr wherein a. from 100 to 1 mol of a stoichiometric mixture of a dicarboxylic acid corresponding to the general formula HO i R E OH in which:

R represents a linear or branched alkylene radical with 4 to carbon atoms, and an araliphatic diamine corresponding to the general formula H N R, (CH NH formula (in which 2 is a single bond or represents a radical selected from the group consisting of O, S, CH2-, (CH2)2 and whose aromatic rings are unsubstituted or substituted either once or several times by halogen or lower alkyl groups; n is an integer from 1 to 4; with b. from 0 to 99 mol a polyamide forming compound selected from the group consisting of a stoichiometric mixture of a dicarboxylic acid corresponding to the general formula and hexamethylene diamine,

a salt corresponding to the general formula a lactam corresponding to the general formula R represents a linear or branched alkylene radical with 4 to 10 carbon atoms; and

and

R represents a linear or branched alkylene radical with 3 to 20 carbon atoms.

The resulting polyamides and copolyamides having aromatic and aliphatic amide groups are eminently suitable for being formed from the melt into shaped structures, particularly into filaments and foils.

The araliphatic diamines having one aromatic and one aliphatic amino group in the molecule which are used in the preparation of the novel polyamides and copolyamides are generally known compounds which can be obtained in high yields by various known processes, for example:

I. By reacting mor p-nitrocarboxylic acid chlorides with ammonia to form the corresponding nitrocarboxylic acid amide, subsequently eliminating the water present (for example using thionyl chloride) to yield the nitrocarboxylic acid nitrile, followed by hydrogenation to produce the araliphatic diamine;

2. by nitrating carboxylic acid nitriles, followed by hydrogenation of the nitro and nitrile group; and

3. exchanging halogen for the nitrile group in nitrohalogen, alkyl aromatic compounds, followed by hydrogenation to produce the araliphatic diamine.

Examples of suitable diamines include the compounds 3-amino benzyl amine, 4-amino benzyl amine. B-(3-amino phenyU-ethyl amine, B(4-amino phenyl)- ethyl amine, 7-(3-amino phenyl)-propyl amine, y-(4- amino phenyl)-propyl amine, 4 amino-4'-amino methyl diphenyl and 4-amino-4'-aminomethyl diphenyl ether.

Suitable aliphatic dicarboxylic acids include those having from 6 to 12 carbon atoms, but especially adipic acid, suberic acid, azelaic acid, sebacic acid and decanol.l0-dicarboxylic acid.

e-caprolactam, 'y-methyl-e-caprolactam and lauric lactam are mentioned by way of example as particularly suitable lactams corresponding to the general formula:

suitable for co-condensation.

In one preferred embodiment of the process according to the invention, polycondensation is carried out by heating a mixture of the starting components with stirring to a temperature of from 100 to 300 C. over a period of from 30 minutes to 18 hours under normal pressure in the presence of an inert gas, for example, nitr0- gen or hydrogen. The starting components are preferably used in equivalent quantities. On completion of the pre-condensation stage, the pressure is reduced, generally to below 15 Torr and preferably to below 1 Torr. Polycondensation is carried out under these conditions for periods of from 15 minutes to 12 hours until the required melt viscosity is obtained. On completion of olycondensation, the polyamide or copolyamide formed can be directly processed from the melt into shaped articles such as filaments, foils or other shaped articles.

The novel polyamides and co-polyamides are distinguished by their outstanding natural colour, by favourable mechanical and thermal properties and by their outstanding ability to be processed. Compared with conventional polyamides and copolyamides which contain aromatic amide groups in the molecule, the new polyamides and co-polyamides have the advantage that the condensation times are shortened when araliphatic diamines as opposed to pure aromatic diamines are used.

As a result, the relatively heavy discolouration of the polycondensate attributable to prolonged condensation times is reduced and also advantages afforded by the introduction of aromatic rings into a polyamide molecule are simultaneously obtained. It is particularly emphasised that the polycondensates obtained in accordance with the invention have a low tendency towards crystallisation and, for this reason, are transparent and have a high gloss.

The relative solution viscosities 17 quoted in the following Examples were measured at 25 C. on solutions of 1 g of substance in 100 ml solution in m-cresol. The following Examples are to further illustrate the invention without limiting it.

EXAMPLE 1 A mixture of 36.5 part" by weight of adipic acid and 305 parts by weight of carefully distilled 3-amino benzyl amine is introduced into a metal bath heated to 160 N l H filament-forming properties. The filaments obtained have a softening point of to 144 C. 17 2.27.

EXAMPLE 2 Following the procedure of Example 1, a mixture of 52.4 parts by weight of hexamethylene diammonium adipate (AH-salt), 6.1 parts by weight of 3-amino benzyl amine and 7.3 parts by weight of adipic acid, is condensed under nitrogen for 15 minutes at C., for 20 minutes at C, for 15 minutes at 220 C., for 15 minutes at 250 C. and for 45 minutes at 270 C. under normal pressure. Thereafter, vacuum is applied, followed by condensation for 30 minutes at 270275C./13 Torr and for 240 minutes at 270C./0.07 Torr. A highly viscous melt which is slightly yellow in colour is obtained from which high strength filaments with favourable coldand hot- EXAMPLE 3 As described in Example 1, 52.4 parts by weight of AH-salt, 7.3 parts by weight of adipic acid and 7.83 parts by weight of 6-chloro-3-amino benzyl amine are condensed under nitrogen for 15 minutes at 160 C., for 20 minutes at 180 C., for 15 minutes at 220 C., for 25 minutes at 250 C. and for 45 minutes at 270 C. under normal pressure and for 30 minutes at 270C./912 Torr and for another 235 minutes at 270C./0.050.03 Torr. A melt with excellent filamentforming properties is obtained. The filaments obtained show outstanding coldand hot-stretching properties coupled with high strength. Softening point 242-250 C. Th

EXAMPLE 4 Following the procedure of Example 1, 41.3 parts by weight of hexamethylene diammonium sebacate (SH- salt), 15.9 parts by weight of 3-amino benzyl amine and 26.3 parts by weight of sebacic acid are heated to 180 C under nitrogen and the mixture is then condensed for 30 minutes at 180 to C, for 30 minutes at 220 C, for 15 minutes at 250 C and for 85 minutes at 275 C under normal pressure. Following the application of vacuum, condensation is continued for 30 minutes at 275 C./20 Torr and for 240 minutes at 275 C./3 Torr. A highly viscous melt is obtained from which filaments with a good natural colour, high strength and favourable stretching properties, can be drawn. Softening point 167 C, n 2.24.

EXAMPLE 5 Under the same reaction conditions as described in Example 1, 52.4 parts by weight of AH-salt, 3.4 parts by weight of B-(4-amino phenyl)-ethyl amine and 3.65 parts by weight of adipic acid are condensed under a nitrogen atmosphere for 15 minutes at 220 C., for 10 of [3-(4-amino phenyl)-ethyl amine and 21.9 parts by minutes at 250 C., for 25 minutes at 275 C. and for weight of adipic acid are condensed for 30 minutes at 65 minutes at 300 C. under normal pressure and for 30 's for 30 minutes t C., for 30 minutes at mi ute t 300C /|8 T d f 230 minutes at 220C, for 345 minutes at 250C. and for 255 minutes 300C./ 1 .5-1 .3 Torr. After this time, an extremely 5 i form a i y Viscous meii with g high-viscosity melt is formed. The resulting filaments meni'fomiihg P p The fiiai'hehts Qbialhefi can show favourable stretching properties, a good natural reaiiiiy f Stretched and have a softening P01ht of colour and outstanding strength. Softening point above 250 'irel 260 C., 1 2.82. '0 EXAMPLE EXAMPLE 6 52.4 Parts by weight of Al-l-salt, 4.28 parts by weight of 4-amlno-4'-am1no methyl dlphenyl ether and 2.92 55.7 Parts by weight of SH-salt. 4.87 parts by weight parts by weight of adipic acid are heated under a nitro- Of p-l phehyii'ethyi amine and Pans by gen atmosphere as in Example 1 in a melt bath to 220 weight of sebacic acid are condensed under a nitrogen C and condensed f 5 m'mmes at C, for 5 atmosphere as in Example i for 15 minutes at utes at 250 C and for 60 minutes at 275 C under norl55-160 C., for 25 minutes at 180 C., for 15 minutes g pressure Following h application f vacuum at for minutes at and for 90 minutes condensation is continued for 30 minutes at 270 to at 275C under normal Pressure following the P 275 C/12 Torr, for 150 minutes at 275 C/0.05 Torr plication 0 ac o minutes at 10 TOrf- 20 and for 70 minutes at 300 C/0.5 to 0.7 Torr, so that a An extremely high'viswsiiy melt with good iiiamehi highly viscous melt is obtained from which almost coforming properties is obtained. The filaments ho lourless, readily stretchable and highly stable filaments favourable coldand hot-stretching properties, coupled can be drawn. Softening point 238-246 C., 11,, 2.26.

l 0 Q with high strengths and a softenmg polnt of 230 -235 25 EXAMPLE 1 1 In the apparatus described in Example 1, 52.4 parts by weight of AH-salt, 8.56 parts by weight of 4-amino- 4'-amino methyl diphenyl ether and 5.84 parts by weight of adipic acid are condensed under a nitrogen atmosphere for 15 minutes at 220-225 C., for 15 min- EXAMPLE 7 As in Example 1, 51.9 parts by weight of the hexamethylene diamine salt of decano-l,l0-dicarboxylic with Parts by weight of phenyn'ethyl utes at 250 C. and for 50 minutes at 27 5 C. under norafnine Pans by weight of f mal pressure, and for 30 minutes at 275C./1 1-15 Torr,

dlcarboxyhc acid are condensed under a nitrogen atfor 115 minutes at To" and for 60 mosphere for 15 minutes at 160 C., for 15 minutes at utes at mono/Q7 To An extremely highwiscosity 1 0 f r 15 min t 2 r 15 minutes at melt is obtained from which filaments with little disand for 60 minutes at under normal colouration can be drawn. Softening point 234240 pressure and then for 20 minutes at 300C./13 Torr and C., n"! 2 for 65 minutes at 300 C./0.l Torr, to form an exw l i y high-Viscosity from which transparent. l. A high molecular weight linear copolyamide conhigh strength filaments with favourable coldand hoti ti ti ll f;

stretching properties can be drawn. Softening point a. recurring structural elements corresponding to the 234236 C., 11 3.12. general formula EXAMPLE 8 where:

R represents a linear or branched alkylene radical with 4 to 10 carbon atoms;

R represents an unsubstituted radical selected from the group consisting of 1,3-phenylene, 1,4- phenylene, 1,4-naphthylene, 1,5-naphthy1ene, 4,4'-diphenylene, and i 45.3 Parts by weight of e-caprolactam, 14.6 parts by weight of adipic acid and 13.6 parts by weight of B-(4- amino phenyl)-ethy1 amine are condensed for 30 minutes at 160 C., for 30 minutes at 180 C., for 30 minutes at 220 C. and for 750 minutes at 250 C. under normal pressure in the apparatus described in Example 1. A high-viscosity melt with little or no discolouration Q is obtained from which stable filaments having good coldand hot-stretching properties can be drawn. Softening point 206-212 C., 17 2.30.

EXAMPLE 9 Under the conditions described in Example 1, 34.0 parts by weight of e-caprolactam, 20.4 parts by weight R, represents substituted radicals selected from the group consisting of 4,4'-dipheny1ene substituted one or more times by halogen or lower alkyl groups and a radical substituted one or more times by halogen or lower alkyl groups of the general formula wherein in the above formulae Z is a member selected from the group consisting of and CH n is an integer from 1 to 4; and

b. less than 90% by weight recurring structural elements corresponding to a general formula selected from the group consisting of thereof wherein:

R represents a linear or branched alkylene radical phenylene, 4,4'-diphenylene ether or R represents a substituted 4,4'-diphenylene ether radical wherein the substitutent is one or more chlorine atoms;

n is an integer from I to 4; and in (b) R is a radical selected from the group consisting of 3. The high molecular claimed in claim 2, wherein R represents (CH 4. The high molecular weight copolyamide as claimed in claim 3, said copolyamide as an essential part of the polymer chain and in copolymerized form at least 10% by weight of the residue of an araliphatic diamine of the general formula weight copolyamide as in which:

R, represents an unsubstituted radical selected from the group consisting of l,3-phenylene, 1,4- phenylene and 4,4'-diphenylene ether or R represents a substitituted 4,4'-diphenylene ether radical wherein the substitutent is one or more chlorine atoms;

n is an integer from 1 to 4.

5. A shaped structure selected from the group consisting of fibers and foils, and comprising the high molecular weight linear copolyamide of claim 1. 

1. A HIGH MOLECULAR WEIGHT LINEAR COPOLYAMINE CONSISTING ESSENTIALLY OF: A. RECURRING STRUCTURAL ELEMENTS CORRESPONDING TO THE GENERAL FORMULA
 2. A high molecular weight linear copolyamide of claim 1 wherein in (a) R represents a radical selected from the group consisting of -(CH2)4-, -(CH2)6-, -(CH2)7-, -(CH2)8-, and -(CH2)10-; R1 represents an unsubstituted radical selected from the group consisting of 1,3-phenylene, 1,4-phenylene, 4,4''-diphenylene ether or R1 represents a substituted 4,4''-diphenylene ether radical wherein the substItutent is one or more chlorine atoms; n is an integer from 1 to 4; and in (b) R2 is a radical selected from the group consisting of -(CH2)5-,
 3. The high molecular weight copolyamide as claimed in claim 2, wherein R2 represents -(CH2)5-.
 4. The high molecular weight copolyamide as claimed in claim 3, said copolyamide as an essential part of the polymer chain and in copolymerized form at least 10% by weight of the residue of an araliphatic diamine of the general formula NH2 - R1 -(CH2)n- NH2 in which: R1 represents an unsubstituted radical selected from the group consisting of 1,3-phenylene, 1,4-phenylene and 4,4''-diphenylene ether or R1 represents a substitituted 4,4''-diphenylene ether radical wherein the substitutent is one or more chlorine atoms; n is an integer from 1 to
 4. 5. A shaped structure selected from the group consisting of fibers and foils, and comprising the high molecular weight linear copolyamide of claim
 1. 